Homogeneous water-based aerosol systems

ABSTRACT

HOMOGENEOUS WATER-BASED AEROSOL SYSTEMS CONTAINING MINOR AMOUNTS OF SILOXANE-POLYVOXYALKYLENE COPOLYMER, SURFACTANT, AND PROPELLANT AND MAJOR AMOUNT OF WATER. THIS COMBINATION RESULTS IN CLEAR AEROSOL COMPOSITIONS WHICH HAVE SUFFICIENT PROPELLENT FOR SATISFACTORY EXHAUSTION FROM AN AEROSOL CONTAINER. THE PROPELLANTS DO NOT LAYER OUT AND ARE NOT EMULSIFIED BUT ARE COMPLETELY DISSOLVED BY THE AQUEOUS CONCENTRATE FORMING A HOMOGENEOUS SYSTEM.

United States Patent 3,655,865 HOMOGENEOUS WATER-BASED AEROSOL SYSTEMS Lawrence J. Murphy, East Brunswick, NJ., assignor to Colgate-Palmolive Company, New York, N.Y. No Drawing. Continuation-impart of application Ser. No. 527,516, Feb. 15, 1966. This application June 8, 1970,

Ser. No. 44,627

Int. Cl. A61k 7/06 US. Cl. 42445 Claims ABSTRACT OF THE DISCLOSURE Homogeneous water-based aerosol systems containing minor amounts of siloxane-polyoxyalkylene copolymer, surfactant, and propellant and major amount of water. This combination results in clear aerosol compositions which have sufiicient propellant for satisfactory exhaustion from an aerosol container. The propellants do not layer out and are not emulsified but are completely dissolved by the aqueous concentrate forming a homogeneous system.

This is a continuation-in-part of application Ser. No. 527,516, filed Feb. 15, 1966, now abandoned.

The present invention relates to homogeneous Waterbased aerosol systems useful as basic ingredients for homogeneous water-based aerosols and also as hair conditioners. The aerosols are dispensed from pressure resistant containers by means of a propellant which at the pressure in the can is liquid but which at ambient tem perature and atmospheric pressure is gaseous.

In general, the product-propellant system in pressure cans can be classified in two groups. Either the product and propellant are maintained separately or the product and propellant are mixed.

The present invention is concerned with the latter class. The present invention relates to the aforesaid homogeneous product-propellant systems in which at least about 80 percent of the product is water. Many water-based aerosols are in use today but they have one of the following drawbacks: 1) Use of a compressed gass propellant which exerts reduced pressure as the product is used changing the nature of the foam or spray dispensed resulting in poor exhaustion or (2) the use of liquefied gases which layer out and usually are flammable. Both systems are subject to rapid exhaustion of pressure by improper dispensing from the container.

The presently contemplated water-based aerosols are advantageous in that they are characterized by substantially uniform pressure within the container as the product is dispensed, thereby maintaining a uniform nature of the foam or spray dispensed and giving excellent exhaustion of the product contained in the can, and also permittig the use of non-flammable propellants.

The product-propellant system contemplated by the present invention is a homogeneous system in which the propellant is completely dissolved in the aqueous product and there is no free propellant nor an emulsion. The propellants of the present system are soluble in the aqueous product, having solubilities of the order of eighty-five (85) cubic centimeters of gas vapor per one hundred (100) grams of water at the vapor pressure of the mixed gases at 25 C.

The products of the present invention typically contain only about eight (8) percent of propellant, which depends for its selection upon its solubility in the aqueous medium present inasmuch as the instant compositions are substantially devoid of alcohol. The compositions of the present invention also require the presence of a cationic or cationic and nonionic surface active agents, but do not employ anionic surface active agents. Suitably the preparations of the present invention have a pH in the range of about 3.5 to about 4.5, i.e., are slightly acid.

Thus it is an object of the present invention to provide a self-propelling homogeneous water-based composition substantially devoid of aliphatic alcohols having one to three carbon atoms. By substantially devoid of said alcohol those skilled in the art will understand that the concentration of the said low molecular Weight alcohols is insufiicient to dissolve the normally gaseous liquid propellant in water. It is another object of the present invention to provide a self-propelling homogeneous water-based composition containing essentially siloxane-polyoxyalkylene block copolymers where in the soloxane moieties are linked to polyoxyalkylene moieties by hydrolytically stable silicon to carbon bonds and have the following tvnical physical properties:

Typical viscosity, 25 C. centistokes: 1800 Specific gravity, 25 C./ 25 C.: 1.032 Pour point, F.: 25 (C48 C.)

Flash point, (COC) F.: 505 (265 C.)

and said by the manufacturer to be represented by the formulas:

(this formula is disclosed in British patent specification 1,015,611 on page 7 line 5 and hereinafter referred to as compound A), and

(hereinafter referred to as compound B), wherein Me is -CH and Bu is -C H and a cationic quaternary ammonium halide in critical proportions and a propellant, soluble in an aqueous solution of said block copolymer and said cationic surfactant, comprising trifluoroethyl chloride.

It is a further object of the present invention to provide a self-propelling homogeneous water-based composition containing essentially block copolymer and a cationic quaternary ammonium halide in critical proportions and a propellant soluble in an aqueous solution of said block copolymer and said cationic surfactant comprising trifluoroethyl chloride. (The admixture of Freon-22 i.e., chlorodifluoromethane; with the trifluoroethyl chloride is not essential but raises the pressure and improves the quality of the foam.) The present invention also provides a self-propelling homogeneous water-based composition containing essentially an organosiloxy compound which is hydrophilic as Well as soluble to some extent in normally gaseous liquid halogenated aliphatic hydrocarbons having not more than two carbon atoms and a cationic surfactant in critical proportions. The present invention provides a concentrate consisting essentially of cationic surfactant, block polymer which is hydrophilic as well as soluble to some extent in normally gaseous liquid halogenated aliphatic hydrocarbons having not more than two carbon atoms in critical proportions and deionized water, said concentrate when mixed with normally gaseous liquid propellant comprising trifiuoroethyl chloride forming a self-propelling homogeneous water-based aerosol containing at least about parts concentrate and up to about 9 parts of normally gaseous liquid propellant comprising trifluoroethyl chloride, or a mixture of trifluoroethyl chloride and chlorodifiuoromethane having a pressure at 77 F. of about 30 p.s.i.g. Other objects and advantages of the present invention will become apparent to those skilled in the art from the following description.

Of the block copolymer compounds which are hydrophilic as well as soluble to some extent in normally gaseous liquid halogenated hydrocarbons having not more than two carbon atoms such as trifluoroethyl chloride, and mixtures of trifluoroethyl chloride and one or more of Freon-BB1 (tri fiuorobromomethane) and Freon- 22 (chlorodifluoromethane), it is presently preferred to use the siloxane-polyalkylene block copolymer said by the manufacturer to be represented by the formula The amount of siloxane-polyoxyalkylene block copolymer in the concentrate formulation may vary from one to three percent (1 to 3%), by weight of concentrate and preferably from one and three-fourths to two and one-half percent (1% to 2 /2%). The most preferred concentrate embodiment contains this material in two percent (2%) by weight of the concentrate.

Illustrative of other siloxane-polyoxyalkylene block copolymers is the block copolymer said by the manufacturer to be represented by the formula M90 (C2H4O) 7C3Hs Meilsio SiO SiMea wherein Me is CH Of the cationic surfactants it is presently preferred to use the quaternary ammonium chloride available from American Alcolac Corporation, Baltimore, Md., which appears to be an oleyl dimethyl benzyl ammonium chloride. Also suitable for use are myristoleyl dimethyl benzyl ammonium chloride, linoleyl dimethyl benzyl ammonium chloride, liuolenyl dimethyl benzyl ammonium chloride, myristyl dimethyl benzyl ammonium chloride, palmityl dimethyl benzyl ammonium chloride, dioleyl dimethyl ammonium chloride, dimyristoleyl dimethyl ammonium chloride, lauryl trimethyl ammonium chloride, palrnityl trimethyl ammonium chloride, tallow trimethyl ammonium chloride, N (lauroyl-colamino-formyl-methyl) pyridinium chloride, 2 myristyl-1-(2-hydroxyethyl)-lpalmityl imidazolium chloride, 2-oleyl-1-(2-hydroxyethyl)-l-lauryl imidazolinium chloride. Other cationic surfactants suitable for the purpose of the present invention are amine oxides which are cationic in the pH range of about 3.5 to about 4.5, e.'g., lauryl dimethyl amine oxide and higher alkyl di-lower alkyl amine oxides. The amount of cationic present in the concentrate can vary from three to about fifteen percent (3 to about 15%) by weight of concentrate and preferably from five to twelve and fivetenths percent (5 to 12.5%). In a preferred concentrate embodiment without nonionic, it is preferable to have the cationic, present in ten percent by weight of the concentrate. When a nonionic is present, it is preferable to have the cationic present in five percent (5%) by weight of the concentrate.

Illustrative of the concentrate which can be mixed with normally gaseous liquid propellant comprising trifluoroethyl chloride (CF CH CI) is the following:

Component: Parts by weight Oleyl dimethyl benzyl ammonium chloride (at 50% active) 10 Block copolymer compound A 2 Perfume 0.2

De-ionized water q.s.

1 Balance to make 100 parts by Weight.

chlorodifiuoromethane (Freon-22) in the proportions indicated by the following:

Trifluoroethyl chloride-8 parts. Chlorodifiuoromethane1 part.

The finished product is prepared by dissolving the propellant in the concentrate under pressure in a hermetically sealed container. The finished product has a pressure of about 30 pounds per square inch gauge (30 p.s.i.-g.). The mixture of concentrate and propellant is a homogeneous clear solution of the propellant in which the normally gaseous liquid propellant is completely dissolved. It is to be noted that under normal storage conditions, i.e., at about 50 to about F., there is no formation of a layer of propellant.

The finished product of the illustrative examples is not only a self-propelling homogeneous composition to which suitable compatible ingredients can be added to provide formulations suitable for a variety of purposes, but is also useful as a hair conditioner. The formulation given hereinbefore dispenses as a foam for conditioning in vivo human hair.

While the propellant in the illustrative example is a mixture of trifluoroethyl chloride and Freon-22, the trifluoroethyl chloride can be used as the sole propellant. Other propellants having higher vapor pressures can be used to raise the pressure of the trifluoroethyl chloride. For example, Freon l3Bl and/or Freon-l2. (dichlorodifiuoromethane) can be used. While the amount of propellant will be less than ten percent (10%) in the finished product, when lesser amounts of active materials,

' i.e., the cationic surfactant and the block copolymer are used, the amount of propellant is reduced as is necessary or desirable to maintain the clarity of the finished product, i.e., to maintain substantially complete solubility of the normally gaseous liquid propellant in the finished product. The amount of propellant should not be more than about ten percent (10%) by weight of the final aerosol composition. Those skilled in the art are cautioned to note that neither the cationic surfactant alone nor the block copolymer alone are effective solubilizers for the trifluoroethyl chloride or the trifluoroethyl -chloride-Freon mixed propellant. Thus, when the concentrate contains about 15 parts of the cationic surfactant to about 3 parts of block copolymer compound A, although the finished product initially is clear with as little as eight parts of trifluoroethyl chloride in one hundred parts of finished product, on standing becomes cloudy. However, when the ratio of cationic surfactant to block copolymer compound A is larger, i.e., less block copolymer is present, a useful amount of propellant can be dissolved to provide a formulation which remains clear after storage.

When desirable or necessary to enhance foaming, nonionic surfactants can be added to the concentrate as illustrated in the following example:

Component: Parts by weight Oleyl dimethyl benzyl ammonium chloride 5 Silicone block copolymer 2 Polyoxyethylene ester of mixed fatty and resin acids derived from tall oil and containing about 16 mols of ethylene oxide 2 Deionized water q.s.

1 Balance to make 100 parts by weight.

The above concentrate can be mixed with normally gaseous liquid propellants as previously stated for the formulations without nonionic.

Illustrative of the nonionic surfactants which can be incorporated into the concentrate are the following: polyoxyethylene esters of mixed fatty and resin acids derived from tall oil and containing about 16 mols of ethylene oxide, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monooleate, condensation products of ethylene oxide with a fatty alcohol, mixtures containing alkylpoly (ethyleneoxy) glycol amine, coconut fatty acids condensed with diethanolamine, nonyl phenoxy poly (ethyleneoxy) ethanol, condensation products of ethylene oxide and an alkyl-phenol, polysorbate 80, polyethylene glycol 1540 monooleate, polyethylene glycol 6000 monooleate, polyethylene mannitan monopalmitate, polyoxyethylene sorbitol laurate, polyoxyethylene propylene glycol monopalmitate, polyoxyethylene sorbitan monolaurate, polypropylene glycol (mol. wt. 900) fatty acid derivatives.

Of the above nonionics, the most preferred is polyoxyethylene esters of mixed fatty and resin acids derived from tall oil and containing about 16 mols of ethylene oxide. This mixture is prepared by Atlas Chemical Industries and available under the trademark Renex 20. Renex is described by the manufacturer as having the following characteristics:

Form at C.--Amber liquid Specific gravity at 25 C.Approx. 1.1 Viscosity at 25 C.-Approx. 350 cps. Pour point-Approx. 55 F.

Cloud point (1% in water)Approx. 126 F. Flash point-Above 300 F.

Fire point-Above 300 F.

HLB number-l3.8

Acid number-2.0 max.

Hydroxyl number-57-67 Water content (percent)-3.0 max.

The amount of nonionic in the concentrate formulation can vary from one to three percent (1 to 3%) by Weight of concentrate, and the preferred embodiment contains two percent (2% The above formulations with or without a nonionic are useful as hair conditioners and dispense as foams. The concentrates are also useful as solubilizers for homogeneous aerosol systems designed for other purposes based on the use of trifluoroethyl chloride.

[1 claim:

1. A substantially clear, homogeneous water-based aerosol composition system comprising a propellant selected from the group consisting of trifluoroethyl chloride and mixtures of trifluoroethyl chloride and normally gaseous liquid halogenated aliphatic hydrocarbons having not more than two carbon atoms and a solubilizing concentrate for said propellant, said concentrate consisting essentially of three to about fifteen percent (3 to about 15%) by weight of a cationic surfactant, zero tothree percent (0 to 3%) by weight of nonionic surfactant, one to three percent (1 to 3%) by weight of si-loxane-polyoxyalkylene block copolymer and the balance water, said propellant being no more than ten percent (10%) by weight of the final system.

2. The homogeneous water-based aerosol system of claim 1 wherein the cationic surfactant is selected from the group consisting of oleyl dimethyl benzyl ammonium chloride, lauryl trimethyl ammonium chloride, tallow trimethyl ammonium chloride, and N(lauroyl-colaminoformyl-methyl) pyridinium chloride.

3. A homogeneous water-based aerosol system of claim 1 wherein the cationic surfactant is oleyl dimethyl benzyl ammonium chloride and ten percent (10%) by weight of the concentrate, the siloxane-polyoxyalkylene block copolymer having the following formula:

and being present as two percent (2%) by weight of the concentrate, and the propellant is a mixture of trifluoroethyl chloride and chlorodifluoromethane and is nine percent (9%) by weight of the final system.

4. A homogeneous water-based aerosol system of claim 1 wherein the concentrate contains one to three percent (1 to 3% by weight of nonionic surfactant.

5. A homogeneous water-based aerosol system of claim 1 wherein the concentrate consists essentially of five percent (5%) by Weight of oleyl dimethyl benzyl ammonium chloride, two percent (2%) by weight of a nonionic surfactant which is polyoxyethylene esters of mixed fatty and resin acids derived from tall oil and containing about 16 mols of ethylene oxide, two percent (2%) by weight of a siloxane-polyoxyalkylene block copolymer having the following formula:

and the propellant is a mixture of trifluoroethyl chloride and chlorodifluoromethane and is nine percent (9%) by weight of the final system.

No references cited.

STANLEY J. FRIEDMAN, Primary Examiner US. Cl. X.R. 42470, 184 

